Regularities of somatic gene mutagenesis in radiation-exposed individuals

Abstract

Somatic mutant cell frequencies at glycophorin A (GPA) and T-cell receptor (TCR) loci were assessed in individuals exposed to ionizing radiation under various circumstances and control unexposed donors. The linear dependences of the GPA (NO) mutant cell frequency on the dose of ionizing radiation were demonstrated for acute and prolonged exposures. Statistically significant correlation between the GPA (NO) and TCR mutant scores was observed only in the group of individuals with recent exposures which had taken place 1–4 years before the analysis ( r=0.75, p<0.05). Some proportion of individuals exposed to low doses of radiation had elevated levels of the GPA and, especially, the TCR mutant cells exceeding the 95% confidence interval in the control group. Taking into account data on the elevation of mutant cell number at both loci in untreated cancer patients, one may suggest that (i) individuals with elevated TCR and/or GPA mutant cell scores belong to a high-risk group potentially prone to the development of neoplasms; (ii) risk of cancer development after low-dose radiation exposure is worth being evaluated separately in individuals with high and low mutant cell frequencies.